/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "compat.h" #include "ctree.h" #include "disk-io.h" #include "transaction.h" #include "btrfs_inode.h" #include "print-tree.h" #include "ordered-data.h" #include "xattr.h" #include "tree-log.h" #include "volumes.h" #include "compression.h" #include "locking.h" #include "free-space-cache.h" #include "inode-map.h" #include "backref.h" struct btrfs_iget_args { u64 ino; struct btrfs_root *root; }; static const struct inode_operations btrfs_dir_inode_operations; static const struct inode_operations btrfs_symlink_inode_operations; static const struct inode_operations btrfs_dir_ro_inode_operations; static const struct inode_operations btrfs_special_inode_operations; static const struct inode_operations btrfs_file_inode_operations; static const struct address_space_operations btrfs_aops; static const struct address_space_operations btrfs_symlink_aops; static const struct file_operations btrfs_dir_file_operations; static struct extent_io_ops btrfs_extent_io_ops; static struct kmem_cache *btrfs_inode_cachep; static struct kmem_cache *btrfs_delalloc_work_cachep; struct kmem_cache *btrfs_trans_handle_cachep; struct kmem_cache *btrfs_transaction_cachep; struct kmem_cache *btrfs_path_cachep; struct kmem_cache *btrfs_free_space_cachep; #define S_SHIFT 12 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = { [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE, [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR, [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV, [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV, [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO, [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK, [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK, }; static int btrfs_setsize(struct inode *inode, struct iattr *attr); static int btrfs_truncate(struct inode *inode); static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock); static struct extent_map *create_pinned_em(struct inode *inode, u64 start, u64 len, u64 orig_start, u64 block_start, u64 block_len, u64 orig_block_len, u64 ram_bytes, int type); static int btrfs_dirty_inode(struct inode *inode); static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, struct inode *inode, struct inode *dir, const struct qstr *qstr) { int err; err = btrfs_init_acl(trans, inode, dir); if (!err) err = btrfs_xattr_security_init(trans, inode, dir, qstr); return err; } /* * this does all the hard work for inserting an inline extent into * the btree. The caller should have done a btrfs_drop_extents so that * no overlapping inline items exist in the btree */ static noinline int insert_inline_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 start, size_t size, size_t compressed_size, int compress_type, struct page **compressed_pages) { struct btrfs_key key; struct btrfs_path *path; struct extent_buffer *leaf; struct page *page = NULL; char *kaddr; unsigned long ptr; struct btrfs_file_extent_item *ei; int err = 0; int ret; size_t cur_size = size; size_t datasize; unsigned long offset; if (compressed_size && compressed_pages) cur_size = compressed_size; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; key.objectid = btrfs_ino(inode); key.offset = start; btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY); datasize = btrfs_file_extent_calc_inline_size(cur_size); inode_add_bytes(inode, size); ret = btrfs_insert_empty_item(trans, root, path, &key, datasize); if (ret) { err = ret; goto fail; } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, ei, trans->transid); btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); btrfs_set_file_extent_encryption(leaf, ei, 0); btrfs_set_file_extent_other_encoding(leaf, ei, 0); btrfs_set_file_extent_ram_bytes(leaf, ei, size); ptr = btrfs_file_extent_inline_start(ei); if (compress_type != BTRFS_COMPRESS_NONE) { struct page *cpage; int i = 0; while (compressed_size > 0) { cpage = compressed_pages[i]; cur_size = min_t(unsigned long, compressed_size, PAGE_CACHE_SIZE); kaddr = kmap_atomic(cpage); write_extent_buffer(leaf, kaddr, ptr, cur_size); kunmap_atomic(kaddr); i++; ptr += cur_size; compressed_size -= cur_size; } btrfs_set_file_extent_compression(leaf, ei, compress_type); } else { page = find_get_page(inode->i_mapping, start >> PAGE_CACHE_SHIFT); btrfs_set_file_extent_compression(leaf, ei, 0); kaddr = kmap_atomic(page); offset = start & (PAGE_CACHE_SIZE - 1); write_extent_buffer(leaf, kaddr + offset, ptr, size); kunmap_atomic(kaddr); page_cache_release(page); } btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); /* * we're an inline extent, so nobody can * extend the file past i_size without locking * a page we already have locked. * * We must do any isize and inode updates * before we unlock the pages. Otherwise we * could end up racing with unlink. */ BTRFS_I(inode)->disk_i_size = inode->i_size; ret = btrfs_update_inode(trans, root, inode); return ret; fail: btrfs_free_path(path); return err; } /* * conditionally insert an inline extent into the file. This * does the checks required to make sure the data is small enough * to fit as an inline extent. */ static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct inode *inode, u64 start, u64 end, size_t compressed_size, int compress_type, struct page **compressed_pages) { u64 isize = i_size_read(inode); u64 actual_end = min(end + 1, isize); u64 inline_len = actual_end - start; u64 aligned_end = ALIGN(end, root->sectorsize); u64 data_len = inline_len; int ret; if (compressed_size) data_len = compressed_size; if (start > 0 || actual_end >= PAGE_CACHE_SIZE || data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) || (!compressed_size && (actual_end & (root->sectorsize - 1)) == 0) || end + 1 < isize || data_len > root->fs_info->max_inline) { return 1; } ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1); if (ret) return ret; if (isize > actual_end) inline_len = min_t(u64, isize, actual_end); ret = insert_inline_extent(trans, root, inode, start, inline_len, compressed_size, compress_type, compressed_pages); if (ret && ret != -ENOSPC) { btrfs_abort_transaction(trans, root, ret); return ret; } else if (ret == -ENOSPC) { return 1; } set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); btrfs_delalloc_release_metadata(inode, end + 1 - start); btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); return 0; } struct async_extent { u64 start; u64 ram_size; u64 compressed_size; struct page **pages; unsigned long nr_pages; int compress_type; struct list_head list; }; struct async_cow { struct inode *inode; struct btrfs_root *root; struct page *locked_page; u64 start; u64 end; struct list_head extents; struct btrfs_work work; }; static noinline int add_async_extent(struct async_cow *cow, u64 start, u64 ram_size, u64 compressed_size, struct page **pages, unsigned long nr_pages, int compress_type) { struct async_extent *async_extent; async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); BUG_ON(!async_extent); /* -ENOMEM */ async_extent->start = start; async_extent->ram_size = ram_size; async_extent->compressed_size = compressed_size; async_extent->pages = pages; async_extent->nr_pages = nr_pages; async_extent->compress_type = compress_type; list_add_tail(&async_extent->list, &cow->extents); return 0; } /* * we create compressed extents in two phases. The first * phase compresses a range of pages that have already been * locked (both pages and state bits are locked). * * This is done inside an ordered work queue, and the compression * is spread across many cpus. The actual IO submission is step * two, and the ordered work queue takes care of making sure that * happens in the same order things were put onto the queue by * writepages and friends. * * If this code finds it can't get good compression, it puts an * entry onto the work queue to write the uncompressed bytes. This * makes sure that both compressed inodes and uncompressed inodes * are written in the same order that the flusher thread sent them * down. */ static noinline int compress_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, struct async_cow *async_cow, int *num_added) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; u64 num_bytes; u64 blocksize = root->sectorsize; u64 actual_end; u64 isize = i_size_read(inode); int ret = 0; struct page **pages = NULL; unsigned long nr_pages; unsigned long nr_pages_ret = 0; unsigned long total_compressed = 0; unsigned long total_in = 0; unsigned long max_compressed = 128 * 1024; unsigned long max_uncompressed = 128 * 1024; int i; int will_compress; int compress_type = root->fs_info->compress_type; int redirty = 0; /* if this is a small write inside eof, kick off a defrag */ if ((end - start + 1) < 16 * 1024 && (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) btrfs_add_inode_defrag(NULL, inode); actual_end = min_t(u64, isize, end + 1); again: will_compress = 0; nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1; nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE); /* * we don't want to send crud past the end of i_size through * compression, that's just a waste of CPU time. So, if the * end of the file is before the start of our current * requested range of bytes, we bail out to the uncompressed * cleanup code that can deal with all of this. * * It isn't really the fastest way to fix things, but this is a * very uncommon corner. */ if (actual_end <= start) goto cleanup_and_bail_uncompressed; total_compressed = actual_end - start; /* we want to make sure that amount of ram required to uncompress * an extent is reasonable, so we limit the total size in ram * of a compressed extent to 128k. This is a crucial number * because it also controls how easily we can spread reads across * cpus for decompression. * * We also want to make sure the amount of IO required to do * a random read is reasonably small, so we limit the size of * a compressed extent to 128k. */ total_compressed = min(total_compressed, max_uncompressed); num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes); total_in = 0; ret = 0; /* * we do compression for mount -o compress and when the * inode has not been flagged as nocompress. This flag can * change at any time if we discover bad compression ratios. */ if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) && (btrfs_test_opt(root, COMPRESS) || (BTRFS_I(inode)->force_compress) || (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) { WARN_ON(pages); pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS); if (!pages) { /* just bail out to the uncompressed code */ goto cont; } if (BTRFS_I(inode)->force_compress) compress_type = BTRFS_I(inode)->force_compress; /* * we need to call clear_page_dirty_for_io on each * page in the range. Otherwise applications with the file * mmap'd can wander in and change the page contents while * we are compressing them. * * If the compression fails for any reason, we set the pages * dirty again later on. */ extent_range_clear_dirty_for_io(inode, start, end); redirty = 1; ret = btrfs_compress_pages(compress_type, inode->i_mapping, start, total_compressed, pages, nr_pages, &nr_pages_ret, &total_in, &total_compressed, max_compressed); if (!ret) { unsigned long offset = total_compressed & (PAGE_CACHE_SIZE - 1); struct page *page = pages[nr_pages_ret - 1]; char *kaddr; /* zero the tail end of the last page, we might be * sending it down to disk */ if (offset) { kaddr = kmap_atomic(page); memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset); kunmap_atomic(kaddr); } will_compress = 1; } } cont: if (start == 0) { trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); trans = NULL; goto cleanup_and_out; } trans->block_rsv = &root->fs_info->delalloc_block_rsv; /* lets try to make an inline extent */ if (ret || total_in < (actual_end - start)) { /* we didn't compress the entire range, try * to make an uncompressed inline extent. */ ret = cow_file_range_inline(trans, root, inode, start, end, 0, 0, NULL); } else { /* try making a compressed inline extent */ ret = cow_file_range_inline(trans, root, inode, start, end, total_compressed, compress_type, pages); } if (ret <= 0) { /* * inline extent creation worked or returned error, * we don't need to create any more async work items. * Unlock and free up our temp pages. */ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY | EXTENT_CLEAR_DELALLOC | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); btrfs_end_transaction(trans, root); goto free_pages_out; } btrfs_end_transaction(trans, root); } if (will_compress) { /* * we aren't doing an inline extent round the compressed size * up to a block size boundary so the allocator does sane * things */ total_compressed = ALIGN(total_compressed, blocksize); /* * one last check to make sure the compression is really a * win, compare the page count read with the blocks on disk */ total_in = ALIGN(total_in, PAGE_CACHE_SIZE); if (total_compressed >= total_in) { will_compress = 0; } else { num_bytes = total_in; } } if (!will_compress && pages) { /* * the compression code ran but failed to make things smaller, * free any pages it allocated and our page pointer array */ for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); page_cache_release(pages[i]); } kfree(pages); pages = NULL; total_compressed = 0; nr_pages_ret = 0; /* flag the file so we don't compress in the future */ if (!btrfs_test_opt(root, FORCE_COMPRESS) && !(BTRFS_I(inode)->force_compress)) { BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; } } if (will_compress) { *num_added += 1; /* the async work queues will take care of doing actual * allocation on disk for these compressed pages, * and will submit them to the elevator. */ add_async_extent(async_cow, start, num_bytes, total_compressed, pages, nr_pages_ret, compress_type); if (start + num_bytes < end) { start += num_bytes; pages = NULL; cond_resched(); goto again; } } else { cleanup_and_bail_uncompressed: /* * No compression, but we still need to write the pages in * the file we've been given so far. redirty the locked * page if it corresponds to our extent and set things up * for the async work queue to run cow_file_range to do * the normal delalloc dance */ if (page_offset(locked_page) >= start && page_offset(locked_page) <= end) { __set_page_dirty_nobuffers(locked_page); /* unlocked later on in the async handlers */ } if (redirty) extent_range_redirty_for_io(inode, start, end); add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0, BTRFS_COMPRESS_NONE); *num_added += 1; } out: return ret; free_pages_out: for (i = 0; i < nr_pages_ret; i++) { WARN_ON(pages[i]->mapping); page_cache_release(pages[i]); } kfree(pages); goto out; cleanup_and_out: extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY | EXTENT_CLEAR_DELALLOC | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); if (!trans || IS_ERR(trans)) btrfs_error(root->fs_info, ret, "Failed to join transaction"); else btrfs_abort_transaction(trans, root, ret); goto free_pages_out; } /* * phase two of compressed writeback. This is the ordered portion * of the code, which only gets called in the order the work was * queued. We walk all the async extents created by compress_file_range * and send them down to the disk. */ static noinline int submit_compressed_extents(struct inode *inode, struct async_cow *async_cow) { struct async_extent *async_extent; u64 alloc_hint = 0; struct btrfs_trans_handle *trans; struct btrfs_key ins; struct extent_map *em; struct btrfs_root *root = BTRFS_I(inode)->root; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_io_tree *io_tree; int ret = 0; if (list_empty(&async_cow->extents)) return 0; again: while (!list_empty(&async_cow->extents)) { async_extent = list_entry(async_cow->extents.next, struct async_extent, list); list_del(&async_extent->list); io_tree = &BTRFS_I(inode)->io_tree; retry: /* did the compression code fall back to uncompressed IO? */ if (!async_extent->pages) { int page_started = 0; unsigned long nr_written = 0; lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1); /* allocate blocks */ ret = cow_file_range(inode, async_cow->locked_page, async_extent->start, async_extent->start + async_extent->ram_size - 1, &page_started, &nr_written, 0); /* JDM XXX */ /* * if page_started, cow_file_range inserted an * inline extent and took care of all the unlocking * and IO for us. Otherwise, we need to submit * all those pages down to the drive. */ if (!page_started && !ret) extent_write_locked_range(io_tree, inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, btrfs_get_extent, WB_SYNC_ALL); else if (ret) unlock_page(async_cow->locked_page); kfree(async_extent); cond_resched(); continue; } lock_extent(io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1); trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); } else { trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = btrfs_reserve_extent(trans, root, async_extent->compressed_size, async_extent->compressed_size, 0, alloc_hint, &ins, 1); if (ret && ret != -ENOSPC) btrfs_abort_transaction(trans, root, ret); btrfs_end_transaction(trans, root); } if (ret) { int i; for (i = 0; i < async_extent->nr_pages; i++) { WARN_ON(async_extent->pages[i]->mapping); page_cache_release(async_extent->pages[i]); } kfree(async_extent->pages); async_extent->nr_pages = 0; async_extent->pages = NULL; if (ret == -ENOSPC) goto retry; goto out_free; } /* * here we're doing allocation and writeback of the * compressed pages */ btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); em = alloc_extent_map(); if (!em) { ret = -ENOMEM; goto out_free_reserve; } em->start = async_extent->start; em->len = async_extent->ram_size; em->orig_start = em->start; em->mod_start = em->start; em->mod_len = em->len; em->block_start = ins.objectid; em->block_len = ins.offset; em->orig_block_len = ins.offset; em->ram_bytes = async_extent->ram_size; em->bdev = root->fs_info->fs_devices->latest_bdev; em->compress_type = async_extent->compress_type; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, async_extent->start, async_extent->start + async_extent->ram_size - 1, 0); } if (ret) goto out_free_reserve; ret = btrfs_add_ordered_extent_compress(inode, async_extent->start, ins.objectid, async_extent->ram_size, ins.offset, BTRFS_ORDERED_COMPRESSED, async_extent->compress_type); if (ret) goto out_free_reserve; /* * clear dirty, set writeback and unlock the pages. */ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK); ret = btrfs_submit_compressed_write(inode, async_extent->start, async_extent->ram_size, ins.objectid, ins.offset, async_extent->pages, async_extent->nr_pages); alloc_hint = ins.objectid + ins.offset; kfree(async_extent); if (ret) goto out; cond_resched(); } ret = 0; out: return ret; out_free_reserve: btrfs_free_reserved_extent(root, ins.objectid, ins.offset); out_free: extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, async_extent->start, async_extent->start + async_extent->ram_size - 1, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); kfree(async_extent); goto again; } static u64 get_extent_allocation_hint(struct inode *inode, u64 start, u64 num_bytes) { struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; struct extent_map *em; u64 alloc_hint = 0; read_lock(&em_tree->lock); em = search_extent_mapping(em_tree, start, num_bytes); if (em) { /* * if block start isn't an actual block number then find the * first block in this inode and use that as a hint. If that * block is also bogus then just don't worry about it. */ if (em->block_start >= EXTENT_MAP_LAST_BYTE) { free_extent_map(em); em = search_extent_mapping(em_tree, 0, 0); if (em && em->block_start < EXTENT_MAP_LAST_BYTE) alloc_hint = em->block_start; if (em) free_extent_map(em); } else { alloc_hint = em->block_start; free_extent_map(em); } } read_unlock(&em_tree->lock); return alloc_hint; } /* * when extent_io.c finds a delayed allocation range in the file, * the call backs end up in this code. The basic idea is to * allocate extents on disk for the range, and create ordered data structs * in ram to track those extents. * * locked_page is the page that writepage had locked already. We use * it to make sure we don't do extra locks or unlocks. * * *page_started is set to one if we unlock locked_page and do everything * required to start IO on it. It may be clean and already done with * IO when we return. */ static noinline int __cow_file_range(struct btrfs_trans_handle *trans, struct inode *inode, struct btrfs_root *root, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock) { u64 alloc_hint = 0; u64 num_bytes; unsigned long ram_size; u64 disk_num_bytes; u64 cur_alloc_size; u64 blocksize = root->sectorsize; struct btrfs_key ins; struct extent_map *em; struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; int ret = 0; BUG_ON(btrfs_is_free_space_inode(inode)); num_bytes = ALIGN(end - start + 1, blocksize); num_bytes = max(blocksize, num_bytes); disk_num_bytes = num_bytes; /* if this is a small write inside eof, kick off defrag */ if (num_bytes < 64 * 1024 && (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) btrfs_add_inode_defrag(trans, inode); if (start == 0) { /* lets try to make an inline extent */ ret = cow_file_range_inline(trans, root, inode, start, end, 0, 0, NULL); if (ret == 0) { extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, NULL, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); *nr_written = *nr_written + (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE; *page_started = 1; goto out; } else if (ret < 0) { btrfs_abort_transaction(trans, root, ret); goto out_unlock; } } BUG_ON(disk_num_bytes > btrfs_super_total_bytes(root->fs_info->super_copy)); alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); while (disk_num_bytes > 0) { unsigned long op; cur_alloc_size = disk_num_bytes; ret = btrfs_reserve_extent(trans, root, cur_alloc_size, root->sectorsize, 0, alloc_hint, &ins, 1); if (ret < 0) { btrfs_abort_transaction(trans, root, ret); goto out_unlock; } em = alloc_extent_map(); if (!em) { ret = -ENOMEM; goto out_reserve; } em->start = start; em->orig_start = em->start; ram_size = ins.offset; em->len = ins.offset; em->mod_start = em->start; em->mod_len = em->len; em->block_start = ins.objectid; em->block_len = ins.offset; em->orig_block_len = ins.offset; em->ram_bytes = ram_size; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); } if (ret) goto out_reserve; cur_alloc_size = ins.offset; ret = btrfs_add_ordered_extent(inode, start, ins.objectid, ram_size, cur_alloc_size, 0); if (ret) goto out_reserve; if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, start, cur_alloc_size); if (ret) { btrfs_abort_transaction(trans, root, ret); goto out_reserve; } } if (disk_num_bytes < cur_alloc_size) break; /* we're not doing compressed IO, don't unlock the first * page (which the caller expects to stay locked), don't * clear any dirty bits and don't set any writeback bits * * Do set the Private2 bit so we know this page was properly * setup for writepage */ op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0; op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_SET_PRIVATE2; extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, start + ram_size - 1, locked_page, op); disk_num_bytes -= cur_alloc_size; num_bytes -= cur_alloc_size; alloc_hint = ins.objectid + ins.offset; start += cur_alloc_size; } out: return ret; out_reserve: btrfs_free_reserved_extent(root, ins.objectid, ins.offset); out_unlock: extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); goto out; } static noinline int cow_file_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written, int unlock) { struct btrfs_trans_handle *trans; struct btrfs_root *root = BTRFS_I(inode)->root; int ret; trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); return PTR_ERR(trans); } trans->block_rsv = &root->fs_info->delalloc_block_rsv; ret = __cow_file_range(trans, inode, root, locked_page, start, end, page_started, nr_written, unlock); btrfs_end_transaction(trans, root); return ret; } /* * work queue call back to started compression on a file and pages */ static noinline void async_cow_start(struct btrfs_work *work) { struct async_cow *async_cow; int num_added = 0; async_cow = container_of(work, struct async_cow, work); compress_file_range(async_cow->inode, async_cow->locked_page, async_cow->start, async_cow->end, async_cow, &num_added); if (num_added == 0) { btrfs_add_delayed_iput(async_cow->inode); async_cow->inode = NULL; } } /* * work queue call back to submit previously compressed pages */ static noinline void async_cow_submit(struct btrfs_work *work) { struct async_cow *async_cow; struct btrfs_root *root; unsigned long nr_pages; async_cow = container_of(work, struct async_cow, work); root = async_cow->root; nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 5 * 1024 * 1024 && waitqueue_active(&root->fs_info->async_submit_wait)) wake_up(&root->fs_info->async_submit_wait); if (async_cow->inode) submit_compressed_extents(async_cow->inode, async_cow); } static noinline void async_cow_free(struct btrfs_work *work) { struct async_cow *async_cow; async_cow = container_of(work, struct async_cow, work); if (async_cow->inode) btrfs_add_delayed_iput(async_cow->inode); kfree(async_cow); } static int cow_file_range_async(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { struct async_cow *async_cow; struct btrfs_root *root = BTRFS_I(inode)->root; unsigned long nr_pages; u64 cur_end; int limit = 10 * 1024 * 1024; clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS); while (start < end) { async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS); BUG_ON(!async_cow); /* -ENOMEM */ async_cow->inode = igrab(inode); async_cow->root = root; async_cow->locked_page = locked_page; async_cow->start = start; if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) cur_end = end; else cur_end = min(end, start + 512 * 1024 - 1); async_cow->end = cur_end; INIT_LIST_HEAD(&async_cow->extents); async_cow->work.func = async_cow_start; async_cow->work.ordered_func = async_cow_submit; async_cow->work.ordered_free = async_cow_free; async_cow->work.flags = 0; nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; atomic_add(nr_pages, &root->fs_info->async_delalloc_pages); btrfs_queue_worker(&root->fs_info->delalloc_workers, &async_cow->work); if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) < limit)); } while (atomic_read(&root->fs_info->async_submit_draining) && atomic_read(&root->fs_info->async_delalloc_pages)) { wait_event(root->fs_info->async_submit_wait, (atomic_read(&root->fs_info->async_delalloc_pages) == 0)); } *nr_written += nr_pages; start = cur_end + 1; } *page_started = 1; return 0; } static noinline int csum_exist_in_range(struct btrfs_root *root, u64 bytenr, u64 num_bytes) { int ret; struct btrfs_ordered_sum *sums; LIST_HEAD(list); ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr, bytenr + num_bytes - 1, &list, 0); if (ret == 0 && list_empty(&list)) return 0; while (!list_empty(&list)) { sums = list_entry(list.next, struct btrfs_ordered_sum, list); list_del(&sums->list); kfree(sums); } return 1; } /* * when nowcow writeback call back. This checks for snapshots or COW copies * of the extents that exist in the file, and COWs the file as required. * * If no cow copies or snapshots exist, we write directly to the existing * blocks on disk */ static noinline int run_delalloc_nocow(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, int force, unsigned long *nr_written) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_trans_handle *trans; struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct btrfs_key found_key; u64 cow_start; u64 cur_offset; u64 extent_end; u64 extent_offset; u64 disk_bytenr; u64 num_bytes; u64 disk_num_bytes; u64 ram_bytes; int extent_type; int ret, err; int type; int nocow; int check_prev = 1; bool nolock; u64 ino = btrfs_ino(inode); path = btrfs_alloc_path(); if (!path) { extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); return -ENOMEM; } nolock = btrfs_is_free_space_inode(inode); if (nolock) trans = btrfs_join_transaction_nolock(root); else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, start, end, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); btrfs_free_path(path); return PTR_ERR(trans); } trans->block_rsv = &root->fs_info->delalloc_block_rsv; cow_start = (u64)-1; cur_offset = start; while (1) { ret = btrfs_lookup_file_extent(trans, root, path, ino, cur_offset, 0); if (ret < 0) { btrfs_abort_transaction(trans, root, ret); goto error; } if (ret > 0 && path->slots[0] > 0 && check_prev) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1); if (found_key.objectid == ino && found_key.type == BTRFS_EXTENT_DATA_KEY) path->slots[0]--; } check_prev = 0; next_slot: leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { btrfs_abort_transaction(trans, root, ret); goto error; } if (ret > 0) break; leaf = path->nodes[0]; } nocow = 0; disk_bytenr = 0; num_bytes = 0; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid > ino || found_key.type > BTRFS_EXTENT_DATA_KEY || found_key.offset > end) break; if (found_key.offset > cur_offset) { extent_end = found_key.offset; extent_type = 0; goto out_check; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); if (extent_type == BTRFS_FILE_EXTENT_REG || extent_type == BTRFS_FILE_EXTENT_PREALLOC) { disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); extent_offset = btrfs_file_extent_offset(leaf, fi); extent_end = found_key.offset + btrfs_file_extent_num_bytes(leaf, fi); disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); if (extent_end <= start) { path->slots[0]++; goto next_slot; } if (disk_bytenr == 0) goto out_check; if (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) goto out_check; if (extent_type == BTRFS_FILE_EXTENT_REG && !force) goto out_check; if (btrfs_extent_readonly(root, disk_bytenr)) goto out_check; if (btrfs_cross_ref_exist(trans, root, ino, found_key.offset - extent_offset, disk_bytenr)) goto out_check; disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; /* * force cow if csum exists in the range. * this ensure that csum for a given extent are * either valid or do not exist. */ if (csum_exist_in_range(root, disk_bytenr, num_bytes)) goto out_check; nocow = 1; } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { extent_end = found_key.offset + btrfs_file_extent_inline_len(leaf, fi); extent_end = ALIGN(extent_end, root->sectorsize); } else { BUG_ON(1); } out_check: if (extent_end <= start) { path->slots[0]++; goto next_slot; } if (!nocow) { if (cow_start == (u64)-1) cow_start = cur_offset; cur_offset = extent_end; if (cur_offset > end) break; path->slots[0]++; goto next_slot; } btrfs_release_path(path); if (cow_start != (u64)-1) { ret = __cow_file_range(trans, inode, root, locked_page, cow_start, found_key.offset - 1, page_started, nr_written, 1); if (ret) { btrfs_abort_transaction(trans, root, ret); goto error; } cow_start = (u64)-1; } if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { struct extent_map *em; struct extent_map_tree *em_tree; em_tree = &BTRFS_I(inode)->extent_tree; em = alloc_extent_map(); BUG_ON(!em); /* -ENOMEM */ em->start = cur_offset; em->orig_start = found_key.offset - extent_offset; em->len = num_bytes; em->block_len = num_bytes; em->block_start = disk_bytenr; em->orig_block_len = disk_num_bytes; em->ram_bytes = ram_bytes; em->bdev = root->fs_info->fs_devices->latest_bdev; em->mod_start = em->start; em->mod_len = em->len; set_bit(EXTENT_FLAG_PINNED, &em->flags); set_bit(EXTENT_FLAG_FILLING, &em->flags); em->generation = -1; while (1) { write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em, 1); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(inode, em->start, em->start + em->len - 1, 0); } type = BTRFS_ORDERED_PREALLOC; } else { type = BTRFS_ORDERED_NOCOW; } ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr, num_bytes, num_bytes, type); BUG_ON(ret); /* -ENOMEM */ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) { ret = btrfs_reloc_clone_csums(inode, cur_offset, num_bytes); if (ret) { btrfs_abort_transaction(trans, root, ret); goto error; } } extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, cur_offset, cur_offset + num_bytes - 1, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_SET_PRIVATE2); cur_offset = extent_end; if (cur_offset > end) break; } btrfs_release_path(path); if (cur_offset <= end && cow_start == (u64)-1) { cow_start = cur_offset; cur_offset = end; } if (cow_start != (u64)-1) { ret = __cow_file_range(trans, inode, root, locked_page, cow_start, end, page_started, nr_written, 1); if (ret) { btrfs_abort_transaction(trans, root, ret); goto error; } } error: err = btrfs_end_transaction(trans, root); if (!ret) ret = err; if (ret && cur_offset < end) extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree, cur_offset, end, locked_page, EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC | EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK); btrfs_free_path(path); return ret; } /* * extent_io.c call back to do delayed allocation processing */ static int run_delalloc_range(struct inode *inode, struct page *locked_page, u64 start, u64 end, int *page_started, unsigned long *nr_written) { int ret; struct btrfs_root *root = BTRFS_I(inode)->root; if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 1, nr_written); } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) { ret = run_delalloc_nocow(inode, locked_page, start, end, page_started, 0, nr_written); } else if (!btrfs_test_opt(root, COMPRESS) && !(BTRFS_I(inode)->force_compress) && !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) { ret = cow_file_range(inode, locked_page, start, end, page_started, nr_written, 1); } else { set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &BTRFS_I(inode)->runtime_flags); ret = cow_file_range_async(inode, locked_page, start, end, page_started, nr_written); } return ret; } static void btrfs_split_extent_hook(struct inode *inode, struct extent_state *orig, u64 split) { /* not delalloc, ignore it */ if (!(orig->state & EXTENT_DELALLOC)) return; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } /* * extent_io.c merge_extent_hook, used to track merged delayed allocation * extents so we can keep track of new extents that are just merged onto old * extents, such as when we are doing sequential writes, so we can properly * account for the metadata space we'll need. */ static void btrfs_merge_extent_hook(struct inode *inode, struct extent_state *new, struct extent_state *other) { /* not delalloc, ignore it */ if (!(other->state & EXTENT_DELALLOC)) return; spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); } /* * extent_io.c set_bit_hook, used to track delayed allocation * bytes in this file, and to maintain the list of inodes that * have pending delalloc work to be done. */ static void btrfs_set_bit_hook(struct inode *inode, struct extent_state *state, unsigned long *bits) { /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; spin_unlock(&BTRFS_I(inode)->lock); } __percpu_counter_add(&root->fs_info->delalloc_bytes, len, root->fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes += len; if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags)) { spin_lock(&root->fs_info->delalloc_lock); if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_add_tail(&BTRFS_I(inode)->delalloc_inodes, &root->fs_info->delalloc_inodes); set_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags); } spin_unlock(&root->fs_info->delalloc_lock); } spin_unlock(&BTRFS_I(inode)->lock); } } /* * extent_io.c clear_bit_hook, see set_bit_hook for why */ static void btrfs_clear_bit_hook(struct inode *inode, struct extent_state *state, unsigned long *bits) { /* * set_bit and clear bit hooks normally require _irqsave/restore * but in this case, we are only testing for the DELALLOC * bit, which is only set or cleared with irqs on */ if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { struct btrfs_root *root = BTRFS_I(inode)->root; u64 len = state->end + 1 - state->start; bool do_list = !btrfs_is_free_space_inode(inode); if (*bits & EXTENT_FIRST_DELALLOC) { *bits &= ~EXTENT_FIRST_DELALLOC; } else if (!(*bits & EXTENT_DO_ACCOUNTING)) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents--; spin_unlock(&BTRFS_I(inode)->lock); } if (*bits & EXTENT_DO_ACCOUNTING) btrfs_delalloc_release_metadata(inode, len); if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID && do_list) btrfs_free_reserved_data_space(inode, len); __percpu_counter_add(&root->fs_info->delalloc_bytes, -len, root->fs_info->delalloc_batch); spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->delalloc_bytes -= len; if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 && test_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags)) { spin_lock(&root->fs_info->delalloc_lock); if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) { list_del_init(&BTRFS_I(inode)->delalloc_inodes); clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, &BTRFS_I(inode)->runtime_flags); } spin_unlock(&root->fs_info->delalloc_lock); } spin_unlock(&BTRFS_I(inode)->lock); } } /* * extent_io.c merge_bio_hook, this must check the chunk tree to make sure * we don't create bios that span stripes or chunks */ int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset, size_t size, struct bio *bio, unsigned long bio_flags) { struct btrfs_root *root = BTRFS_I(page->mapping->host)->root; u64 logical = (u64)bio->bi_sector << 9; u64 length = 0; u64 map_length; int ret; if (bio_flags & EXTENT_BIO_COMPRESSED) return 0; length = bio->bi_size; map_length = length; ret = btrfs_map_block(root->fs_info, rw, logical, &map_length, NULL, 0); /* Will always return 0 with map_multi == NULL */ BUG_ON(ret < 0); if (map_length < length + size) return 1; return 0; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_start(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); BUG_ON(ret); /* -ENOMEM */ return 0; } /* * in order to insert checksums into the metadata in large chunks, * we wait until bio submission time. All the pages in the bio are * checksummed and sums are attached onto the ordered extent record. * * At IO completion time the cums attached on the ordered extent record * are inserted into the btree */ static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret; ret = btrfs_map_bio(root, rw, bio, mirror_num, 1); if (ret) bio_endio(bio, ret); return ret; } /* * extent_io.c submission hook. This does the right thing for csum calculation * on write, or reading the csums from the tree before a read */ static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio, int mirror_num, unsigned long bio_flags, u64 bio_offset) { struct btrfs_root *root = BTRFS_I(inode)->root; int ret = 0; int skip_sum; int metadata = 0; int async = !atomic_read(&BTRFS_I(inode)->sync_writers); skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; if (btrfs_is_free_space_inode(inode)) metadata = 2; if (!(rw & REQ_WRITE)) { ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata); if (ret) goto out; if (bio_flags & EXTENT_BIO_COMPRESSED) { ret = btrfs_submit_compressed_read(inode, bio, mirror_num, bio_flags); goto out; } else if (!skip_sum) { ret = btrfs_lookup_bio_sums(root, inode, bio, NULL); if (ret) goto out; } goto mapit; } else if (async && !skip_sum) { /* csum items have already been cloned */ if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) goto mapit; /* we're doing a write, do the async checksumming */ ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info, inode, rw, bio, mirror_num, bio_flags, bio_offset, __btrfs_submit_bio_start, __btrfs_submit_bio_done); goto out; } else if (!skip_sum) { ret = btrfs_csum_one_bio(root, inode, bio, 0, 0); if (ret) goto out; } mapit: ret = btrfs_map_bio(root, rw, bio, mirror_num, 0); out: if (ret < 0) bio_endio(bio, ret); return ret; } /* * given a list of ordered sums record them in the inode. This happens * at IO completion time based on sums calculated at bio submission time. */ static noinline int add_pending_csums(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_offset, struct list_head *list) { struct btrfs_ordered_sum *sum; list_for_each_entry(sum, list, list) { trans->adding_csums = 1; btrfs_csum_file_blocks(trans, BTRFS_I(inode)->root->fs_info->csum_root, sum); trans->adding_csums = 0; } return 0; } int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end, struct extent_state **cached_state) { WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0); return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end, cached_state, GFP_NOFS); } /* see btrfs_writepage_start_hook for details on why this is required */ struct btrfs_writepage_fixup { struct page *page; struct btrfs_work work; }; static void btrfs_writepage_fixup_worker(struct btrfs_work *work) { struct btrfs_writepage_fixup *fixup; struct btrfs_ordered_extent *ordered; struct extent_state *cached_state = NULL; struct page *page; struct inode *inode; u64 page_start; u64 page_end; int ret; fixup = container_of(work, struct btrfs_writepage_fixup, work); page = fixup->page; again: lock_page(page); if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { ClearPageChecked(page); goto out_page; } inode = page->mapping->host; page_start = page_offset(page); page_end = page_offset(page) + PAGE_CACHE_SIZE - 1; lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0, &cached_state); /* already ordered? We're done */ if (PagePrivate2(page)) goto out; ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); unlock_page(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE); if (ret) { mapping_set_error(page->mapping, ret); end_extent_writepage(page, ret, page_start, page_end); ClearPageChecked(page); goto out; } btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state); ClearPageChecked(page); set_page_dirty(page); out: unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end, &cached_state, GFP_NOFS); out_page: unlock_page(page); page_cache_release(page); kfree(fixup); } /* * There are a few paths in the higher layers of the kernel that directly * set the page dirty bit without asking the filesystem if it is a * good idea. This causes problems because we want to make sure COW * properly happens and the data=ordered rules are followed. * * In our case any range that doesn't have the ORDERED bit set * hasn't been properly setup for IO. We kick off an async process * to fix it up. The async helper will wait for ordered extents, set * the delalloc bit and make it safe to write the page. */ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end) { struct inode *inode = page->mapping->host; struct btrfs_writepage_fixup *fixup; struct btrfs_root *root = BTRFS_I(inode)->root; /* this page is properly in the ordered list */ if (TestClearPagePrivate2(page)) return 0; if (PageChecked(page)) return -EAGAIN; fixup = kzalloc(sizeof(*fixup), GFP_NOFS); if (!fixup) return -EAGAIN; SetPageChecked(page); page_cache_get(page); fixup->work.func = btrfs_writepage_fixup_worker; fixup->page = page; btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work); return -EBUSY; } static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, struct inode *inode, u64 file_pos, u64 disk_bytenr, u64 disk_num_bytes, u64 num_bytes, u64 ram_bytes, u8 compression, u8 encryption, u16 other_encoding, int extent_type) { struct btrfs_root *root = BTRFS_I(inode)->root; struct btrfs_file_extent_item *fi; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key ins; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; /* * we may be replacing one extent in the tree with another. * The new extent is pinned in the extent map, and we don't want * to drop it from the cache until it is completely in the btree. * * So, tell btrfs_drop_extents to leave this extent in the cache. * the caller is expected to unpin it and allow it to be merged * with the others. */ ret = btrfs_drop_extents(trans, root, inode, file_pos, file_pos + num_bytes, 0); if (ret) goto out; ins.objectid = btrfs_ino(inode); ins.offset = file_pos; ins.type = BTRFS_EXTENT_DATA_KEY; ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi)); if (ret) goto out; leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_type(leaf, fi, extent_type); btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes); btrfs_set_file_extent_offset(leaf, fi, 0); btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes); btrfs_set_file_extent_compression(leaf, fi, compression); btrfs_set_file_extent_encryption(leaf, fi, encryption); btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); inode_add_bytes(inode, num_bytes); ins.objectid = disk_bytenr; ins.offset = disk_num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_alloc_reserved_file_extent(trans, root, root->root_key.objectid, btrfs_ino(inode), file_pos, &ins); out: btrfs_free_path(path); return ret; } /* snapshot-aware defrag */ struct sa_defrag_extent_backref { struct rb_node node; struct old_sa_defrag_extent *old; u64 root_id; u64 inum; u64 file_pos; u64 extent_offset; u64 num_bytes; u64 generation; }; struct old_sa_defrag_extent { struct list_head list; struct new_sa_defrag_extent *new; u64 extent_offset; u64 bytenr; u64 offset; u64 len; int count; }; struct new_sa_defrag_extent { struct rb_root root; struct list_head head; struct btrfs_path *path; struct inode *inode; u64 file_pos; u64 len; u64 bytenr; u64 disk_len; u8 compress_type; }; static int backref_comp(struct sa_defrag_extent_backref *b1, struct sa_defrag_extent_backref *b2) { if (b1->root_id < b2->root_id) return -1; else if (b1->root_id > b2->root_id) return 1; if (b1->inum < b2->inum) return -1; else if (b1->inum > b2->inum) return 1; if (b1->file_pos < b2->file_pos) return -1; else if (b1->file_pos > b2->file_pos) return 1; /* * [------------------------------] ===> (a range of space) * |<--->| |<---->| =============> (fs/file tree A) * |<---------------------------->| ===> (fs/file tree B) * * A range of space can refer to two file extents in one tree while * refer to only one file extent in another tree. * * So we may process a disk offset more than one time(two extents in A) * and locate at the same extent(one extent in B), then insert two same * backrefs(both refer to the extent in B). */ return 0; } static void backref_insert(struct rb_root *root, struct sa_defrag_extent_backref *backref) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; struct sa_defrag_extent_backref *entry; int ret; while (*p) { parent = *p; entry = rb_entry(parent, struct sa_defrag_extent_backref, node); ret = backref_comp(backref, entry); if (ret < 0) p = &(*p)->rb_left; else p = &(*p)->rb_right; } rb_link_node(&backref->node, parent, p); rb_insert_color(&backref->node, root); } /* * Note the backref might has changed, and in this case we just return 0. */ static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id, void *ctx) { struct btrfs_file_extent_item *extent; struct btrfs_fs_info *fs_info; struct old_sa_defrag_extent *old = ctx; struct new_sa_defrag_extent *new = old->new; struct btrfs_path *path = new->path; struct btrfs_key key; struct btrfs_root *root; struct sa_defrag_extent_backref *backref; struct extent_buffer *leaf; struct inode *inode = new->inode; int slot; int ret; u64 extent_offset; u64 num_bytes; if (BTRFS_I(inode)->root->root_key.objectid == root_id && inum == btrfs_ino(inode)) return 0; key.objectid = root_id; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; fs_info = BTRFS_I(inode)->root->fs_info; root = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(root)) { if (PTR_ERR(root) == -ENOENT) return 0; WARN_ON(1); pr_debug("inum=%llu, offset=%llu, root_id=%llu\n", inum, offset, root_id); return PTR_ERR(root); } key.objectid = inum; key.type = BTRFS_EXTENT_DATA_KEY; if (offset > (u64)-1 << 32) key.offset = 0; else key.offset = offset; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { WARN_ON(1); return ret; } while (1) { cond_resched(); leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) { goto out; } else if (ret > 0) { ret = 0; goto out; } continue; } path->slots[0]++; btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid > inum) goto out; if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY) continue; extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr) continue; extent_offset = btrfs_file_extent_offset(leaf, extent); if (key.offset - extent_offset != offset) continue; num_bytes = btrfs_file_extent_num_bytes(leaf, extent); if (extent_offset >= old->extent_offset + old->offset + old->len || extent_offset + num_bytes <= old->extent_offset + old->offset) continue; break; } backref = kmalloc(sizeof(*backref), GFP_NOFS); if (!backref) { ret = -ENOENT; goto out; } backref->root_id = root_id; backref->inum = inum; backref->file_pos = offset + extent_offset; backref->num_bytes = num_bytes; backref->extent_offset = extent_offset; backref->generation = btrfs_file_extent_generation(leaf, extent); backref->old = old; backref_insert(&new->root, backref); old->count++; out: btrfs_release_path(path); WARN_ON(ret); return ret; } static noinline bool record_extent_backrefs(struct btrfs_path *path, struct new_sa_defrag_extent *new) { struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info; struct old_sa_defrag_extent *old, *tmp; int ret; new->path = path; list_for_each_entry_safe(old, tmp, &new->head, list) { ret = iterate_inodes_from_logical(old->bytenr, fs_info, path, record_one_backref, old); BUG_ON(ret < 0 && ret != -ENOENT); /* no backref to be processed for this extent */ if (!old->count) { list_del(&old->list); kfree(old); } } if (list_empty(&new->head)) return false; return true; } static int relink_is_mergable(struct extent_buffer *leaf, struct btrfs_file_extent_item *fi, u64 disk_bytenr) { if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr) return 0; if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) return 0; if (btrfs_file_extent_compression(leaf, fi) || btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)) return 0; return 1; } /* * Note the backref might has changed, and in this case we just return 0. */ static noinline int relink_extent_backref(struct btrfs_path *path, struct sa_defrag_extent_backref *prev, struct sa_defrag_extent_backref *backref) { struct btrfs_file_extent_item *extent; struct btrfs_file_extent_item *item; struct btrfs_ordered_extent *ordered; struct btrfs_trans_handle *trans; struct btrfs_fs_info *fs_info; struct btrfs_root *root; struct btrfs_key key; struct extent_buffer *leaf; struct old_sa_defrag_extent *old = backref->old; struct new_sa_defrag_extent *new = old->new; struct inode *src_inode = new->inode; struct inode *inode; struct extent_state *cached = NULL; int ret = 0; u64 start; u64 len; u64 lock_start; u64 lock_end; bool merge = false; int index; if (prev && prev->root_id == backref->root_id && prev->inum == backref->inum && prev->file_pos + prev->num_bytes == backref->file_pos) merge = true; /* step 1: get root */ key.objectid = backref->root_id; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; fs_info = BTRFS_I(src_inode)->root->fs_info; index = srcu_read_lock(&fs_info->subvol_srcu); root = btrfs_read_fs_root_no_name(fs_info, &key); if (IS_ERR(root)) { srcu_read_unlock(&fs_info->subvol_srcu, index); if (PTR_ERR(root) == -ENOENT) return 0; return PTR_ERR(root); } if (btrfs_root_refs(&root->root_item) == 0) { srcu_read_unlock(&fs_info->subvol_srcu, index); /* parse ENOENT to 0 */ return 0; } /* step 2: get inode */ key.objectid = backref->inum; key.type = BTRFS_INODE_ITEM_KEY; key.offset = 0; inode = btrfs_iget(fs_info->sb, &key, root, NULL); if (IS_ERR(inode)) { srcu_read_unlock(&fs_info->subvol_srcu, index); return 0; } srcu_read_unlock(&fs_info->subvol_srcu, index); /* step 3: relink backref */ lock_start = backref->file_pos; lock_end = backref->file_pos + backref->num_bytes - 1; lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end, 0, &cached); ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); if (ordered) { btrfs_put_ordered_extent(ordered); goto out_unlock; } trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); goto out_unlock; } key.objectid = backref->inum; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = backref->file_pos; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) { goto out_free_path; } else if (ret > 0) { ret = 0; goto out_free_path; } extent = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_generation(path->nodes[0], extent) != backref->generation) goto out_free_path; btrfs_release_path(path); start = backref->file_pos; if (backref->extent_offset < old->extent_offset + old->offset) start += old->extent_offset + old->offset - backref->extent_offset; len = min(backref->extent_offset + backref->num_bytes, old->extent_offset + old->offset + old->le